#include<stdio.h>

double calc(int depth,int p,int q){
  if(depth>=20){
    return 0.5;
  }
  if(p<=0){
    return 1.0/3.0+calc(depth+1,q,q)/3.0;
  } else if(p>=100){
    return 1.0/2.0+calc(depth+1,100-q,q)/2.0;
  }
  return (1.0/2.0+calc(depth+1,p-q,q)/2.0)*p/100.0
    +(1.0/3.0+calc(depth+1,p+q,q)/3.0)*(100-p)/100.0;
}

void run(void){
  int p,q;
  scanf("%d%d",&p,&q);

  double ans=1.0/3.0+calc(0,p,q)/3.0;
  printf("%.6lf\n",ans);
  return;
}

int main(void){
  run();
  return 0;
}